organic compounds
8,9-Dimethoxybenzo[b]naphtho[2,3-d]thiophene
aDepartment of Physics, Presidency College (Autonomous), Chennai 600 005, India
*Correspondence e-mail: ksakthimurugesan2492@gmail.com
In the title compound, C18H14O2S, the system of four fused rings is almost planar (r.m.s. deviation = 0.022 Å). The C atoms of the methoxy groups deviate from the mean plane of the ring system by 0.373 (2) and −0.104 (2) Å. In the crystal, very weak aromatic π–π stacking interactions [shortest centroid–centroid separation = 3.9286 (10) Å] may help to establish the packing.
Keywords: crystal structure; thiophene; dimethoxybenzene..
CCDC reference: 1590246
Structure description
Thiophene and thiazole derivatives are known to possess interesting biological properties, such as anticancer activity (Bondock et al., 2010; Al-Said et al., 2011). As part of our studies in this area, we now describe the synthesis and structure of the title compound (Fig. 1).
As expected, the thiophene system is essentially planar and subtends dihedral angles with respect to the mean planes through the naphthalene ring system, i.e. the C7–C18 and C1–C6 phenyl rings, of 1.05 (9) and 1.53 (7)°, respectively. The C atoms of the methoxy groups are slightly displaced from their attached benzene ring, as indicated by the C15—C14—O1—C13 and C10—C11—O2—C12 torsion angles of −4.5 (2) and −9.1 (3)°, respectively. In the crystal, very weak aromatic π–π stacking interactions [shortest centroid–centroid separation = 3.9286 (10) Å between inversion-related C7–C9/C16–C18 rings] may help to establish the packing.
Synthesis and crystallization
To a solution of diethyl 2-[(2-(bromomethyl)benzo[b]thiophen-3-yl)methylidene]malonate (0.20 g, 0.50 mmol) and veratrole (1,2-dimethoxybenzene) (0.08 g, 0.55 mmol) in dry dichloroethane (5 ml) was added ZnBr2 (0.03 g, 0.10 mmol). The reaction mixture was then stirred at room temperature under a nitrogen atmosphere for 4 h. After completion of the reaction (monitored by TLC), it was poured into ice water (30 ml). The organic layer was separated and the aqueous layer was extracted with DCM (2 × 20 ml). The combined organic layer was washed with water (2 × 20 ml) and dried (Na2SO4). Removal of the solvent followed by work-up and (silica gel; 4% ethyl acetate in hexane) furnished the title compound (0.10 g, 30%) as a colourless solid (m.p. 463–465 K).
Refinement
Crystal data, data collection and structure .
details are summarized in Table 1Structural data
CCDC reference: 1590246
https://doi.org/10.1107/S2414314618012579/hb4248sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618012579/hb4248Isup2.hkl
Data collection: APEX2 (Bruker, 2008); cell
SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015); molecular graphics: ORTEP-3 (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).C18H14O2S | F(000) = 616 |
Mr = 294.35 | Dx = 1.414 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 13.0062 (9) Å | Cell parameters from 2344 reflections |
b = 5.9631 (4) Å | θ = 3.8–29.1° |
c = 18.3801 (14) Å | µ = 0.24 mm−1 |
β = 104.019 (7)° | T = 293 K |
V = 1383.05 (17) Å3 | Colourless, block |
Z = 4 | 0.30 × 0.30 × 0.25 mm |
Bruker SMART APEXII CCD diffractometer | 2344 reflections with I > 2σ(I) |
ω and φ scans | Rint = 0.028 |
Absorption correction: multi-scan | θmax = 29.1°, θmin = 3.8° |
Tmin = 0.932, Tmax = 0.943 | h = −17→17 |
6823 measured reflections | k = −8→7 |
3192 independent reflections | l = −23→22 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.047 | H-atom parameters constrained |
wR(F2) = 0.119 | w = 1/[σ2(Fo2) + (0.0564P)2 + 0.0382P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
3192 reflections | Δρmax = 0.26 e Å−3 |
192 parameters | Δρmin = −0.44 e Å−3 |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.71269 (4) | 0.65668 (8) | 0.07885 (3) | 0.04428 (18) | |
C7 | 0.63867 (13) | 1.0145 (3) | 0.13423 (9) | 0.0299 (4) | |
C8 | 0.56269 (13) | 1.1552 (3) | 0.15027 (9) | 0.0307 (4) | |
H8 | 0.583331 | 1.286299 | 0.177266 | 0.037* | |
O1 | 0.13171 (9) | 0.9465 (2) | 0.05384 (7) | 0.0436 (3) | |
O2 | 0.18546 (9) | 1.2955 (2) | 0.13568 (8) | 0.0448 (3) | |
C16 | 0.42315 (13) | 0.9019 (3) | 0.08384 (9) | 0.0306 (4) | |
C6 | 0.75384 (13) | 1.0333 (3) | 0.15487 (9) | 0.0311 (4) | |
C17 | 0.50106 (13) | 0.7594 (3) | 0.06797 (10) | 0.0361 (4) | |
H17 | 0.481504 | 0.627975 | 0.040908 | 0.043* | |
C15 | 0.31383 (13) | 0.8491 (3) | 0.05877 (10) | 0.0344 (4) | |
H15 | 0.293603 | 0.720126 | 0.030484 | 0.041* | |
C14 | 0.23822 (13) | 0.9833 (3) | 0.07530 (9) | 0.0321 (4) | |
C9 | 0.45404 (13) | 1.1018 (3) | 0.12604 (9) | 0.0296 (4) | |
C10 | 0.37291 (13) | 1.2380 (3) | 0.14356 (9) | 0.0322 (4) | |
H10 | 0.391553 | 1.368253 | 0.171457 | 0.039* | |
C18 | 0.60588 (13) | 0.8151 (3) | 0.09257 (10) | 0.0324 (4) | |
C11 | 0.26907 (14) | 1.1807 (3) | 0.12021 (10) | 0.0324 (4) | |
C1 | 0.80319 (13) | 0.8525 (3) | 0.12815 (10) | 0.0352 (4) | |
C4 | 0.92672 (15) | 1.1857 (3) | 0.20944 (11) | 0.0456 (5) | |
H4 | 0.968898 | 1.296438 | 0.237431 | 0.055* | |
C2 | 0.91295 (14) | 0.8391 (3) | 0.14075 (11) | 0.0442 (5) | |
H2 | 0.944654 | 0.718409 | 0.122655 | 0.053* | |
C5 | 0.81721 (14) | 1.1985 (3) | 0.19670 (10) | 0.0387 (4) | |
H5 | 0.786216 | 1.317639 | 0.216149 | 0.046* | |
C13 | 0.09704 (14) | 0.7594 (3) | 0.00580 (11) | 0.0457 (5) | |
H13A | 0.127027 | 0.768290 | −0.036975 | 0.069* | |
H13B | 0.021131 | 0.760951 | −0.010592 | 0.069* | |
H13C | 0.119651 | 0.622921 | 0.032647 | 0.069* | |
C12 | 0.21008 (15) | 1.4723 (3) | 0.18900 (12) | 0.0471 (5) | |
H12A | 0.251238 | 1.414300 | 0.235742 | 0.071* | |
H12B | 0.145632 | 1.536265 | 0.196376 | 0.071* | |
H12C | 0.249993 | 1.585695 | 0.170861 | 0.071* | |
C3 | 0.97356 (15) | 1.0083 (4) | 0.18057 (11) | 0.0475 (5) | |
H3 | 1.046885 | 1.003689 | 0.188240 | 0.057* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0379 (3) | 0.0404 (3) | 0.0547 (3) | 0.0074 (2) | 0.0116 (2) | −0.0117 (2) |
C7 | 0.0330 (9) | 0.0315 (9) | 0.0252 (8) | 0.0021 (7) | 0.0070 (7) | 0.0002 (7) |
C8 | 0.0342 (9) | 0.0275 (8) | 0.0298 (9) | −0.0006 (7) | 0.0067 (7) | −0.0033 (7) |
O1 | 0.0292 (6) | 0.0453 (7) | 0.0542 (8) | −0.0016 (5) | 0.0062 (6) | −0.0118 (6) |
O2 | 0.0354 (7) | 0.0431 (7) | 0.0573 (9) | 0.0049 (6) | 0.0137 (6) | −0.0145 (6) |
C16 | 0.0314 (9) | 0.0294 (8) | 0.0309 (9) | 0.0008 (7) | 0.0074 (7) | −0.0027 (7) |
C6 | 0.0319 (9) | 0.0365 (9) | 0.0252 (8) | 0.0014 (7) | 0.0078 (7) | 0.0023 (7) |
C17 | 0.0375 (10) | 0.0306 (9) | 0.0390 (10) | 0.0019 (8) | 0.0067 (8) | −0.0104 (8) |
C15 | 0.0347 (9) | 0.0319 (9) | 0.0353 (9) | −0.0012 (7) | 0.0063 (8) | −0.0081 (7) |
C14 | 0.0307 (9) | 0.0327 (9) | 0.0316 (9) | −0.0003 (7) | 0.0053 (7) | 0.0016 (7) |
C9 | 0.0339 (9) | 0.0283 (8) | 0.0269 (8) | 0.0011 (7) | 0.0079 (7) | −0.0015 (7) |
C10 | 0.0360 (9) | 0.0288 (9) | 0.0321 (9) | 0.0021 (7) | 0.0088 (7) | −0.0044 (7) |
C18 | 0.0337 (9) | 0.0308 (9) | 0.0330 (9) | 0.0048 (7) | 0.0090 (7) | −0.0025 (7) |
C11 | 0.0347 (9) | 0.0313 (9) | 0.0327 (9) | 0.0063 (7) | 0.0110 (7) | 0.0008 (7) |
C1 | 0.0349 (9) | 0.0383 (10) | 0.0332 (9) | 0.0045 (7) | 0.0099 (8) | 0.0035 (8) |
C4 | 0.0376 (10) | 0.0595 (13) | 0.0368 (10) | −0.0082 (9) | 0.0033 (8) | −0.0015 (9) |
C2 | 0.0377 (10) | 0.0525 (12) | 0.0444 (11) | 0.0104 (9) | 0.0138 (9) | 0.0041 (9) |
C5 | 0.0364 (10) | 0.0482 (11) | 0.0311 (9) | 0.0016 (8) | 0.0074 (8) | −0.0031 (8) |
C13 | 0.0369 (10) | 0.0452 (11) | 0.0494 (11) | −0.0032 (9) | −0.0007 (9) | −0.0052 (10) |
C12 | 0.0516 (12) | 0.0414 (11) | 0.0515 (12) | 0.0096 (9) | 0.0185 (10) | −0.0096 (9) |
C3 | 0.0324 (9) | 0.0685 (14) | 0.0403 (11) | 0.0019 (10) | 0.0066 (8) | 0.0068 (10) |
S1—C1 | 1.7475 (18) | C15—H15 | 0.9300 |
S1—C18 | 1.7481 (17) | C14—C11 | 1.438 (2) |
C7—C8 | 1.382 (2) | C9—C10 | 1.429 (2) |
C7—C18 | 1.422 (2) | C10—C11 | 1.358 (2) |
C7—C6 | 1.458 (2) | C10—H10 | 0.9300 |
C8—C9 | 1.411 (2) | C1—C2 | 1.392 (2) |
C8—H8 | 0.9300 | C4—C5 | 1.388 (2) |
O1—C14 | 1.3631 (19) | C4—C3 | 1.389 (3) |
O1—C13 | 1.427 (2) | C4—H4 | 0.9300 |
O2—C11 | 1.3720 (19) | C2—C3 | 1.377 (3) |
O2—C12 | 1.422 (2) | C2—H2 | 0.9300 |
C16—C17 | 1.406 (2) | C5—H5 | 0.9300 |
C16—C15 | 1.420 (2) | C13—H13A | 0.9600 |
C16—C9 | 1.426 (2) | C13—H13B | 0.9600 |
C6—C5 | 1.391 (2) | C13—H13C | 0.9600 |
C6—C1 | 1.403 (2) | C12—H12A | 0.9600 |
C17—C18 | 1.369 (2) | C12—H12B | 0.9600 |
C17—H17 | 0.9300 | C12—H12C | 0.9600 |
C15—C14 | 1.358 (2) | C3—H3 | 0.9300 |
C1—S1—C18 | 91.32 (8) | C7—C18—S1 | 112.60 (12) |
C8—C7—C18 | 119.06 (15) | C10—C11—O2 | 125.90 (15) |
C8—C7—C6 | 129.84 (15) | C10—C11—C14 | 120.35 (15) |
C18—C7—C6 | 111.08 (14) | O2—C11—C14 | 113.74 (14) |
C7—C8—C9 | 120.59 (15) | C2—C1—C6 | 121.58 (17) |
C7—C8—H8 | 119.7 | C2—C1—S1 | 125.64 (14) |
C9—C8—H8 | 119.7 | C6—C1—S1 | 112.78 (13) |
C14—O1—C13 | 116.85 (13) | C5—C4—C3 | 120.30 (18) |
C11—O2—C12 | 117.09 (13) | C5—C4—H4 | 119.9 |
C17—C16—C15 | 120.92 (15) | C3—C4—H4 | 119.9 |
C17—C16—C9 | 119.72 (15) | C3—C2—C1 | 118.58 (17) |
C15—C16—C9 | 119.35 (15) | C3—C2—H2 | 120.7 |
C5—C6—C1 | 118.54 (16) | C1—C2—H2 | 120.7 |
C5—C6—C7 | 129.23 (15) | C4—C5—C6 | 120.05 (17) |
C1—C6—C7 | 112.22 (15) | C4—C5—H5 | 120.0 |
C18—C17—C16 | 119.64 (15) | C6—C5—H5 | 120.0 |
C18—C17—H17 | 120.2 | O1—C13—H13A | 109.5 |
C16—C17—H17 | 120.2 | O1—C13—H13B | 109.5 |
C14—C15—C16 | 121.27 (15) | H13A—C13—H13B | 109.5 |
C14—C15—H15 | 119.4 | O1—C13—H13C | 109.5 |
C16—C15—H15 | 119.4 | H13A—C13—H13C | 109.5 |
C15—C14—O1 | 125.49 (15) | H13B—C13—H13C | 109.5 |
C15—C14—C11 | 119.62 (15) | O2—C12—H12A | 109.5 |
O1—C14—C11 | 114.88 (14) | O2—C12—H12B | 109.5 |
C8—C9—C16 | 119.28 (15) | H12A—C12—H12B | 109.5 |
C8—C9—C10 | 122.57 (14) | O2—C12—H12C | 109.5 |
C16—C9—C10 | 118.13 (15) | H12A—C12—H12C | 109.5 |
C11—C10—C9 | 121.20 (15) | H12B—C12—H12C | 109.5 |
C11—C10—H10 | 119.4 | C2—C3—C4 | 120.91 (18) |
C9—C10—H10 | 119.4 | C2—C3—H3 | 119.5 |
C17—C18—C7 | 121.70 (15) | C4—C3—H3 | 119.5 |
C17—C18—S1 | 125.70 (13) | ||
C18—C7—C8—C9 | 0.3 (2) | C8—C7—C18—S1 | −179.18 (12) |
C6—C7—C8—C9 | −178.41 (16) | C6—C7—C18—S1 | −0.24 (18) |
C8—C7—C6—C5 | 0.4 (3) | C1—S1—C18—C17 | −179.24 (17) |
C18—C7—C6—C5 | −178.38 (17) | C1—S1—C18—C7 | −0.07 (14) |
C8—C7—C6—C1 | 179.31 (17) | C9—C10—C11—O2 | 178.01 (15) |
C18—C7—C6—C1 | 0.5 (2) | C9—C10—C11—C14 | −1.7 (3) |
C15—C16—C17—C18 | 179.70 (16) | C12—O2—C11—C10 | −9.1 (3) |
C9—C16—C17—C18 | −0.6 (3) | C12—O2—C11—C14 | 170.64 (15) |
C17—C16—C15—C14 | 178.51 (16) | C15—C14—C11—C10 | 2.6 (2) |
C9—C16—C15—C14 | −1.1 (3) | O1—C14—C11—C10 | −178.48 (16) |
C16—C15—C14—O1 | −179.95 (16) | C15—C14—C11—O2 | −177.11 (15) |
C16—C15—C14—C11 | −1.2 (3) | O1—C14—C11—O2 | 1.8 (2) |
C13—O1—C14—C15 | −4.5 (2) | C5—C6—C1—C2 | −1.9 (3) |
C13—O1—C14—C11 | 176.69 (15) | C7—C6—C1—C2 | 179.11 (15) |
C7—C8—C9—C16 | −0.8 (2) | C5—C6—C1—S1 | 178.45 (13) |
C7—C8—C9—C10 | 177.72 (15) | C7—C6—C1—S1 | −0.57 (18) |
C17—C16—C9—C8 | 1.0 (2) | C18—S1—C1—C2 | −179.29 (16) |
C15—C16—C9—C8 | −179.36 (15) | C18—S1—C1—C6 | 0.37 (14) |
C17—C16—C9—C10 | −177.62 (15) | C6—C1—C2—C3 | 0.1 (3) |
C15—C16—C9—C10 | 2.0 (2) | S1—C1—C2—C3 | 179.73 (14) |
C8—C9—C10—C11 | −179.17 (16) | C3—C4—C5—C6 | 0.0 (3) |
C16—C9—C10—C11 | −0.6 (2) | C1—C6—C5—C4 | 1.8 (3) |
C16—C17—C18—C7 | 0.1 (3) | C7—C6—C5—C4 | −179.37 (17) |
C16—C17—C18—S1 | 179.24 (13) | C1—C2—C3—C4 | 1.8 (3) |
C8—C7—C18—C17 | 0.0 (3) | C5—C4—C3—C2 | −1.8 (3) |
C6—C7—C18—C17 | 178.97 (16) |
Acknowledgements
The authors thank the Department of Chemistry, Pondicherry University, India, for
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